.. _echo-server-sample:
Echo Server
###########
Overview
********
The echo-server sample application for Zephyr implements a UDP/TCP server
that complements the echo-client sample application: the echo-server listens
for incoming IPv4 or IPv6 packets (sent by the echo client) and simply sends
them back.
The source code for this sample application can be found at:
:file:`samples/net/echo_server`.
Requirements
************
- :ref:`networking_with_qemu`
Building and Running
********************
There are multiple ways to use this application. One of the most common
usage scenario is to run echo-server application inside QEMU. This is
described in :ref:`networking_with_qemu`.
There are configuration files for different boards and setups in the
echo-server directory:
- :file:`prj_arduino_101.conf`
Use this for Arduino 101 with external enc28j60 ethernet board.
- :file:`prj_bt.conf`
Use this for Bluetooth IPSP connectivity.
- :file:`prj_cc2520.conf`
Use this for devices that have support for IEEE 802.15.4 cc2520 chip.
- :file:`prj_frdm_k64f_cc2520.conf`
Use this for FRDM-K64F board with external IEEE 802.15.4 cc2520 board.
- :file:`prj_frdm_k64f.conf`
Use this for FRDM-K64F board with built-in ethernet.
- :file:`prj_frdm_k64f_mcr20a.conf`
Use this for FRDM-K64F board with IEEE 802.15.4 mcr20a board.
- :file:`prj_qemu_802154.conf`
Use this when simulating IEEE 802.15.4 network using two QEMU's that
are connected together.
- :file:`prj_qemu_cortex_m3.conf`
Use this for ARM QEMU.
- :file:`prj_qemu_x86.conf`
Use this for x86 QEMU.
- :file:`prj_sam_e70_xplained.conf`
Use this for Atmel SMART SAM E70 Xplained board with ethernet.
- :file:`prj_netusb.conf`
Use this for Ethernet over USB setup with supported boards. The setup is
described in :ref:`usb_device_networking_setup`.
Build echo-server sample application like this:
.. zephyr-app-commands::
:zephyr-app: samples/net/echo_server
:board: <board to use>
:conf: <config file to use>
:goals: build
:compact:
Make can select the default configuration file based on the BOARD you've
specified automatically so you might not always need to mention it.
Running echo-client in Linux Host
=================================
There is one useful testing scenario that can be used with Linux host.
Here echo-server is run in QEMU and echo-client is run in Linux host.
To use QEMU for testing, follow the :ref:`networking_with_qemu` guide.
Run echo-server application in QEMU:
.. zephyr-app-commands::
:zephyr-app: samples/net/echo_server
:board: qemu_x86
:goals: run
:compact:
In a terminal window:
.. code-block:: console
$ sudo ./echo-client -i tap0 2001:db8::1
Note that echo-server must be running in QEMU before you start the
echo-client application in host terminal window.